Low sudsing liquid detergent compositions

ABSTRACT

PCT No. PCT/US94/07200 Sec. 371 Date Apr. 4, 1996 Sec. 102(e) Date Apr. 4, 1996 PCT Filed Jun. 22, 1994 PCT Pub. No. WO95/00117 PCT Pub. Date Jan. 5, 1995Liquid detergent compositions containing a branched anionic surfactant. These compositions are low sudsing and have improved hydrophobic greasy soil removal performance.

TECHNICAL FIELD

The present invention relates to low sudsing liquid detergentcompositions.

BACKGROUND OF THE INVENTION

Anionic surfactant compositions are well known in the art and aredesirable components in liquid detergents due to their good cleaningability, especially with respect to hydrophobic greasy soil removal.However, the incorporation of anionic surfactants in typical detergentcompositions results in high sudsing formulations.

A number of systems have been described in the art for use in detergentcompositions in order to counter act the sudsing ability of thesurfactants. Such suds suppressing systems include anti-foam agents suchas silicone. However, anti-foam agents have problems associated withthem such as the difficulty to maintain them as a dispersion in liquidcompositions. In addition silicone anti-foam agents are difficult toprocess and are expensive.

Therefore it is an object of the present invention to provide a liquiddetergent composition comprising an anionic surfactant, said compositionhaving a controlled sudsing profile, said composition requiring aminimum amount of conventional suds suppressing agents.

It has now been found that this can be achieved by formulating a liquiddetergent composition comprising a conventional anionic surfactant incombination with an -branched anionic surfactant.

It has unexpectedly been found that such surfactant combinations providecontrolled sudsing, and simultaneously improve said compositions'performance on hydrophobic greasy soil removal.

Another advantage of the present invention is that the sudsing isreduced by the adaptation of straight chain anionic surfactants to their-branched counterparts, i.e. Guerbet anionic surfactants and thus othersuds suppressing agent may only be required in minimum amounts.

Another advantage of the present invention is that the surfactants areeasier to formulate due to the increased solubility of the surfactant.Furthermore, said compositions are easier to form as `concentrated`compositions because of the almost total omission of conventional sudssuppressing agents. In addition the compositions are cheaper toformulate.

Another advantage of the compositions of the present invention is thatsaid compositions are phase stable.

The term "Guerbet" surfactant as used herein refers to branchedsurfactants derived from 2-alkyl-alkanol.

Guerbet surfactants are known in the art. DE 41 11 335 discloses a lowsudsing ternary surfactant mixture comprising an alkylglycoside, linearand branched secondary dialkylethersulphates and sulphate and sulphonateanionic surfactants. There is no specific mention of Guerbet anionicsurfactants.

WO 91/16409 discloses a liquid detergent composition comprising branchedprimary alkyl sulphates. There is no mention of suds suppressingproperties or any specific mention of Guerbet anionic surfactants.

SUMMARY OF THE INVENTION

The present invention is a liquid detergent composition comprising oneor more of an anionic surfactant, characterized in that said anionicsurfactant comprises from 1% to 99% by weight of said anionic surfactantof a compound according to the formula: ##STR1## wherein R₁ is a C₃ -C₂₂alkyl group, R₂ is a C₃ -C₂₂ alkyl group. m is 2, 3 or 4, n is between 0and 14 and R₃ is a sulphate or a sulphonate.

All weights ratios and percentages are given by the weight of the totalcomposition unless otherwise stated.

DETAILED DESCRIPTION OF THE INVENTION

The detergent compositions according to the present invention comprisean anionic surfactant, characterized in that said anionic surfactantcomprises from 1% to 99% by weight of said anionic surfactant of acompound according to the formula: ##STR2## herein after referred to asGuerbet anionic surfactant. Said Guerbet anionic surfactants are lowsudsing due to the -branching. The compositions of the present inventionrequire only a minimum amount of other suds suppressing agents. Saidamount as used herein being an amount less than that used inconventional liquid detergents comprising anionic surfactants.

According to the present invention R₁ is a C₃ -C₂₂, preferably a C₃-C₁₀, more preferably a C₃ -C₈ alkyl group. Said R₁ alkyl group may belinear or branched, saturated or unsaturated. R₂ is a C₃ -C₂₂,preferably a C₆ -C₁₄, more preferably a C₆ -C₁₂ alkyl group. Said R₂alkyl group may be linear or branched, saturated or unsaturated. n isbetween 0 and 14, preferably between 0 and 7, more preferably between 0and 5. R₃ is a sulphate or a sulphonate or mixtures thereof.

The Guerbet anionic surfactant is typically present at levels from 1 to70%, preferably from 5 to 50%, more preferably from 5 to 25% by weightof the total detergent composition.

According to the present invention the compositions may further comprisenon Guerbet anionic surfactants. Suitable anionic surfactants areselected from the group of sulphates and sulphonates. The like anionicsurfactants are well known in the detergent art and have found wideapplication in commercial detergents. Preferred anionic sulphates andsulphonates have in their molecular structure an alkyl radicalcontaining from about 8 to about 22 carbon atoms. Examples of suchpreferred anionic surfactants are the reaction products obtained bysulphating C₈ -C₁₈ fatty alcohols derived from e.g. tallow oil, palmoil, palm kernel oil and coconut oil; alkyl benzene sulphonates whereinthe alkyl group contains from about 9 to about 15 carbon atoms;sodiumalkylglyceryl ether sulphonates; ether sulphates of fatty alcoholsderived from tallow and coconut oils; coconut fatty acid monoglyceridesulphates and sulphonates; water soluble salts of paraffin sulphonateshaving from about 8 to about 22 carbon atoms in the alkyl chain.Sulphonated olefin surfactants as more fully described in e.g. U.S. Pat.No. 3,332,880 can also be used. The neutralizing cation for the anionicsynthetic sulphonates and/or sulphates is represented by conventionalcations which are widely used in detergent technology such as sodium,potassium or alkanolammonium.

A suitable anionic synthetic surfactant component herein is representedby the water soluble salts of an alkylbenzene sulphonic acid, preferablysodium alkylbenzene sulphonates, preferably sodium alkylbenzenesulphonates having from about 10 to 15 carbon atoms in the alkyl group.

Another anionic surfactant suitable for use herein can be alkylalkoxylated sulphate surfactants. Alkyl alkoxylated sulphate surfactantshereof are water soluble salts or acids of the formula RO(A)_(m) SO₃ Mwherein R is an unsubstituted C₁₀ -C₂₄ alkyl or hydroxylalkyl grouphaving a C₁₀ -C₂₄ alkyl component, preferably a C₁₂ -C₁₈ alkyl orhydroxylalkyl, A is an ethoxy or propoxy unit, m is greater than zero,typically between about 0.5 and about 6, more preferably between about0.5 and 3, and M is H or a cation which can be for example a metalcation (e.g. sodium, potassium, lithium, calcium, magnesium, etc.),ammonium or substituted-ammonium cation. Alkyl ethoxylated sulphates aswell as alkyl propoxylated sulphates are contemplated herein. Specificexamples of substituted ammonium cations include methyl-, dimethyl,trimethyl-ammonium cations and those derived from alkanolamines, eg.monoethanolamine, diethanolamine and triethanolamine. Exemplarysurfactants are C₁₂ -C₁₈ alkyl polyethoxylate (1.0) sulphate (C₁₂ -C₁₈E(1.0)M), C₁₂ -C₁₈ alkyl polyethoxylate (2.25) sulphate (C₁₂ -C₁₈E(2.25)M), C₁₂ -C₁₈ alkyl polyethoxylate (3.0) sulphate (C₁₂ -C₁₈E(3.0)M), C₁₂ -C₁₈ alkyl polyethoxylate (4.0) sulphate (C₁₂ -C₁₈E(4.0)M), wherein M is conveniently selected from sodium and potassium.

Another type of anionic surfactant suitable for use herein are alkylester sulphonate, which can be synthesized according to known methodsdisclosed in the technical literature. For instance, linear esters of C₈-C₂₀ carboxylic acids can be sulphonated with gaseous SO₃ according to"The Journal of the American Oil Chemists Society", 52 (1975), pp.323-329. Suitable starting materials would include natural fattysubstances as derived from tallow, palm and coconut oils. The preferredalkyl ester sulphonate, comprise alkyl ester sulphonates of thestructural formula ##STR3## wherein R₄ is a C₈ -C₂₀ hydrocarbyl,preferably an alkyl or combination thereof R₅ is a C₁ -C₆ hydrocarbyl,preferably an alkyl or combination thereof and M is a soluble saltforming cation. Suitable salts include metal salts such as sodium,potassium and lithium salts and substituted or unsubstituted ammoniumsalts, such as methyl-, dimethyl-, trimethyl and dimethyl piperdiniumand cations derived from alkanolamines, e.g. monoethanolamine,diethanolamine and triethanolamine. Preferably R₄ is C₁₀ -C₁₆ alkyl andR₅ is methyl, ethyl or isopropyl. Especially preferred are the methylester sulphonates wherein R₄ is C₁₄ -C₁₆ alkyl.

When included herein, the non-Guerbet anionics are present at levelsfrom 1% to 40%, preferably from 3% to 20%, by weight of the totaldetergent composition.

The rest of the liquid detergent composition according to the presentinvention is made of conventional detergency ingredients, i.e. water,surfactants, builders and others.

The liquid detergent compositions herein may additionally comprise as anoptional ingredient from 1% to 50%, preferably from 5% to 25% of anorganic surface-active agent selected from nonionic, cationic andzwitterionic surface active agents and mixtures thereof.

The nonionic surfactants suitable for use herein include those producedby condensing ethylene oxide with a hydrocarbon having a reactivehydrogen atom, e.g., a hydroxyl, carboxyl, or amido group, in thepresence of an acidic or basic catalyst, and include compounds havingthe general formula RA(CH₂ CH₂ O)_(n) H wherein R represents thehydrophobic moiety, A represents the group carrying the reactivehydrogen atom and n represents the average number of ethylene oxidemoieties. R typically contains from about 8 to 22 carbon atoms They canalso be formed by the condensation of propylene oxide with a lowermolecular weight compound. n usually varies from about 2 to about 24.

A preferred class of nonionic ethoxylates is represented by thecondensation product of a fatty alcohol having from 12 to 15 carbonatoms and from about 4 to 10 moles of ethylene oxide per mole or fattyalcohol. Suitable species of this class of ethoxylates include: thecondensation product of C₁₂ -C₁₅ oxo-alcohols and 3 to 9 moles ofethylene oxide per mole of alcohol; the condensation product or narrowcut C₁₄ -C₁₅ oxo-alcohols and 3 to 9 moles of ethylene oxide per mole offatty(oxo)alcohol; the condensation product of a narrow cut C₁₂ -C₁₃fatty(oxo)alcohol and 6,5 moles of ethylene oxide per mole of fattyalcohol; and the condensation products of a C₁₀ -C₁₄ coconut fattyalcohol with a degree of ethoxylation (moles EO/mole fatty alcohol) inthe range from 4 to 8. The fatty oxo alcohols while mainly linear canhave, depending upon the processing conditions and raw material olefins,a certain degree of branching, particularly short chain such as methylbranching. A degree of branching in the range from 15% to 50% (weight %)is frequently found in commercial oxo alcohols.

The compositions according to the present invention contain from 0% to30% preferably from 0% to 10% of nonionic surfactants.

Suitable cationic surfactants for use herein include quaternary ammoniumcompounds of the formula R₁ R₂ R₃ R₄ N⁺ where R₁,R₂ and R₃ are methylgroups, and R₄ is a C₁₂ -C₁₅ alkyl group, or where R₁ is an ethyl orhydroxy ethyl group. R₂ and R₃ are methyl groups and R₄ is a C₁₂ -C₁₅alkyl group. The compositions according to the present invention containfrom 0% to 20% of cationic surfactants.

Another optional ingredient are zwitterionic surfactants. Suitablezwitterionic surfactants include derivatives of aliphatic quaternaryammonium, phosphonium, and sulphonium compounds in which the aliphaticmoiety can be straight or branched chain and wherein one of thealiphatic substituents contains from about 8 to about 24 carbon atomsand another substituent contains, at least, an anionicwater-solubilizing group. Particularly preferred zwitterionic materialsare the ethoxvlated ammonium sulphonates and sulfates disclosed in U.S.Pat. Nos. 3,925,262, Laughlin et al., issued Dec. 9, 1975 and 3,929,678,Laughlin et al., issued Dec. 30, 1975. The compositions according to thepresent invention contain from 0% to 20% of zwitterionic surfactants.

Semi-polar nonionic surfactants include water-soluble amine oxidescontaining one alkyl or hydroxy alkyl moiety of from about 8 to about 28carbon atoms and two moieties selected from the group consisting ofalkyl groups and hydroxy alkyl groups, containing from 1 to about 3carbon atoms which can optionally be joined into ring structures.

Also suitable as nonionic surfactants are poly hydroxy fatty acid amidesurfactants of the formula

    R.sup.2 -C(O)-N(R.sup.1)-Z,

wherein R¹ is H, or R¹ is C₁₋₄ hydrocarbyl, 2-hydroxy ethyl, 2-hydroxypropyl or a mixture thereof, R² is C₅₋₃₁ hydrocarbyl, and Z is apolyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3hydroxyls directly connected to the chain, or an alkoxylated derivativethereof. Preferably, R¹ is methyl, R² is a straight C₁₁₋₁₅ alkyl oralkenyl chain such as coconut alkyl or mixtures thereof, and Z isderived from a reducing sugar such as glucose, fructose, maltose,lactose, in a reductive amination reaction.

The compositions according to the present invention may further comprisea builder system. Any conventional builder system is suitable for useherein including polycarboxylates and fatty acids, materials such asethylenediamine tetraacetate, metal ion sequestrants such asaminopolyphosphonates, particularly ethylenediamine tetramethylenephosphonic acid and diethylene triamine pentamethylenephosphonic acid.Though less preferred for obvious environmental reasons, phosphatebuilders can also be used herein.

Suitable polycarboxylates builders for use herein include citric acid,preferably in the form of a water-soluble salt, derivatives of succinicacid of the formula R₋₋ CH(COOH)CH₂ (COOH) wherein R is C₁₀₋₂₀ alkyl oralkenyl, preferably C₁₂₋₁₆, or wherein R can be substituted withhydroxyl, sulpho sulphoxyl or sulphone substituents. Specific examplesinclude lauryl succinate, myristyl succinate, palmityl succinate,2-dodecenylsuccinate, 2-tetradecenyl succinate. Succinate builders arepreferably used in the form of their water-soluble salts, includingsodium, potassium ammonium and alkanolammonium salts.

Other suitable polycarboxylates are oxodisuccinates and mixtures oftartrate monosuccinic and tartrate disuccinic acid such as described inU.S Pat. No. 4,663,071.

Suitable fatty acid builders for use herein are saturated or unsaturatedC₁₀₋₁₈ fatty acids, as well as the corresponding soaps. Preferredsaturated species have from 12 to 16 carbon atoms in the alkyl chain.The preferred unsaturated fatty acid is oleic acid.

A preferred builder system for use herein consists of a mixture ofcitric acid, fatty acids and succinic acid derivatives described hereinabove. The builder system according to the present invention preferablyrepresents from 0% to 30%, preferably from 5% to 25% by weight of thetotal composition.

The compositions according to the invention preferably comprise enzymes.Suitable enzymes for use herein are protease, lipases, cellulases andamylases and mixtures thereof. The compositions according to the presentinvention may also comprise an enzyme stabilizing system. Anyconventional enzyme stabilizing system is suitable for use herein, andpreferred enzyme stabilizing systems are based on boric acid orderivatives thereof, 1,2-propanediol, carboxylic acids, and mixturesthereof The compositions according to the present invention contain from0% to 15%, more preferably from 0% to 5% of enzymes.

The compositions herein can contain a series of further, optionalingredients. Examples of the like additives include solvents,alkanolamines, pH adjusting agents, suds suppressing agents such assilicones and 2-alkyl-alkanol, opacifiers, agents to improve the machinecompatibility in relation to enamel-coated surfaces, perfumes, dyes,bactericides, brighteners, soil release agents, softening agents and thelike.

The compositions according to the present invention can be formulated asconventional liquid detergent compositions or, as an alternative asso-called "concentrated" liquid detergent compositions, i.e. liquiddetergent compositions comprising less than 30% by weight of water.

Whilst the detergent compositions of the invention are of particularutility in machine washing processes, most especially when formulated asheavy duty liquid laundry detergent compositions, they may also beusefully be employed in other washing processes where suds control is ofimportance. In particular the compositions of the invention may beusefully be formulated as machine dishwashing compositions, especiallygranular machine dishwashing compositions.

EXAMPLES

The following compositions are made by combining, the followingingredients in the listed proportions.

    ______________________________________    Composition in %  A      B      C    D    E    ______________________________________    Branched C.sub.12 -C.sub.15 alkyl                      5      10     20   25   --    sulphate*    Branched C.sub.12 -C.sub.15 alkyl                      --     --     --   --   25    3EO sulphate**    Linear C.sub.12 -C.sub.14 alkyl sulphate                      15     10     1    1    --    Fatty alcohol (C.sub.12 -C.sub.15 ) ethoxylate                      12     12     12   12   12    Fatty acid        10     10     10   10   10    Oleic acid        4      4      4    4    4    Citric acid       1      1      1    1    1    Diethylenetriaminepenta-                      1.5    1.5    1.5  1.5  1.5    methylene phosphonic acid    Monoethanolamine  3      3      3    3    3    Propanediol       1.5    1.5    1.5  1.5  1.5    Ethanol           10     10     10   10   10    Ethoxylated tetraethylene pentamine                      0.7    0.7    0.7  0.7  0.7    Thermamyl.sup.R 300 KNU/g                      0.13   0.13   0.13 0.13 0.13    Carezyme.sup.R 5000 CEVU/g                      0.014  0.014  0.014                                         0.014                                              0.014    Protease 40 mg/g  1.8    1.8    1.8  1.8  1.8    Lipolase.sup.R 100 KLU/g                      0.14   0.14   0.14 0.14 0.14    Endoglucanase A 5000 CEVU/g                      0.53   0.53   0.53 0.53 0.53    Water & Minors (suds                      up to 1 00 parts    suppressors, perfume)    pH adjusted to 7.5-9 with NaOH    ______________________________________     *Lial C.sub.12 -C.sub.15 alkyl sulphate Na salt prepared from the Lial     C.sub.12 -C.sub.15 alcohol available from Enichem     **Lial C.sub.12 -C.sub.15 alkyl ethoxy sulphate Na salt prepared from the     Lial C.sub.12 -C.sub.15 alcohol 3 times ethoxylated available from Emiche

What is claimed is:
 1. A liquid detergent composition comprising one ormore of an anionic surfactant having the formula: ##STR4## wherein R₁ isa C₃ -C₂₂ alkyl group, R₂ is a C₃ -C₂₂ alkyl group, m is 2, 3 or 4, n isbetween about 3 and 14 and R₃ is a sulphate or a sulphonate.
 2. A liquiddetergent composition according to claim 1, wherein R₁ is preferably aC₃ -C₁₀ alkyl group and R₂ is preferably a C₆ -C₁₄ alkyl group, n isbetween 0 and 7 and R₃ is a sulphate or a sulphonate.
 3. A liquiddetergent composition according to claim 1, wherein R₂ is C₆ -C₁₂ alkylgroup, R₁ is C₃ -C₈ alkyl group and R₃ is a sulphate.
 4. A liquiddetergent composition according to claim 1, wherein the anionicsurfactant is present at a level of from 1 to 70%, by weight of thedetergent composition.
 5. A liquid detergent composition according toclaim 1, further comprising an anionic surfactant selected from alkylsulphates, alkylbenzene sulphonates, alkyl alkoxylated sulphates andalkyl ester sulphonates.
 6. A liquid detergent composition according toclaim 1, wherein the anionic surfactant is present at a level of from 5to 50%, by weight of the detergent composition.
 7. A liquid detergentcomposition according to claim 1, wherein the anionic surfactant ispresent at a level of from 5 to 25%, by weight of the detergentcomposition.
 8. A liquid detergent composition comprising one or more ofan anionic surfactant having the formula: ##STR5## wherein R₁ is a C₃-C₂₂ alkyl group, R₂ is a C₃ -C₂₂ alkyl group, m is 2, 3 or 4, n is 0and R₃ is a sulphate.